Background: Each year, more than 25,000 patients over the age of 75 start maintenance dialysis treatment in the United States. Although dialysis may prolong life, it entails profound and sometimes burdensome changes in lifestyle, substantial risks for complications, and for older adults, a high likelihood of permanent disability. The quality of dialysis decision making is often poor; few patients receive prognostic information or discuss the option to receive medical management without dialysis. Rather, patients perceive these decisions as a choice between dialysis or death. Significance/Impact: Our overarching goal is to support informed, goal-concordant dialysis decisions by developing decision support tools, addressing HSRD Priority Domain `Healthcare Informatics'. This project will address the information needs of patients and clinicians by generating new tools to support informed decision- making and goal-concordant care for Veterans with advanced chronic kidney disease and end-stage renal disease. Innovation: The project is innovative in several ways. First, it applies causal inference models to estimate treatment effects of dialysis to address an important clinical question for which a clinical trial is not feasible. Second, it incorporates patient-centered outcomes to evaluate the effectiveness of dialysis. Third, it uses novel scenario planning frameworks to address uncertainty with decision support. Specific Aims and Methods: To accomplish this goal, we will (1) compare survival, hospital-free survival, time to nursing home placement and number of dialysis access procedures using causal inference models to illustrate trade-offs from dialysis versus medical management among older Veterans with end-stage renal disease; (2) develop a web-based risk benefit calculator and decision aid based on the framework of scenario planning that incorporates estimates of survival and treatment complications with dialysis initiation compared to medical management; and (3) using mixed methods, evaluate the tools' usability, acceptability and effects on patient knowledge and decisional conflict. Implementation/Next Steps: We will work with operational partners to ensure the tools meet the needs of the end-users, and develop plans for broader testing and dissemination. By the end of the project period, we expect to submit a proposal to test a dialysis decision support intervention incorporating these tools in older Veterans.